Merge branch '489072-buy-now-links-to-compare-page' into 'master'

Update the trial discover buy now button to link to billings page

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/171831



Merged-by: Elwyn Benson <ebenson@gitlab.com>
Approved-by: Daniel Tian <dtian@gitlab.com>
Approved-by: Lee Tickett <ltickett@gitlab.com>
Approved-by: Michael Kozono <mkozono@gitlab.com>
Approved-by: Elwyn Benson <ebenson@gitlab.com>
Reviewed-by: Lee Tickett <ltickett@gitlab.com>
Co-authored-by: david hamp-gonsalves <dhamp-gonsalves@gitlab.com>